<template>
<!-- 评论列表 -->
    <div class="cmt_container">
      <div class="com_list_content">
          <van-list
              v-model="loading"
              :finished="finished"
              finished-text="没有更多了"
              @load="onLoad"
              offset="50"
              :immediate-check="false"
            >
              <!-- 评论列表 -->
              <div
              class="cmt-list"
              >
                <!-- 评论的 Item 项 -->
                <div
                class="cmt-item"
                v-for="item in commentList"
              :key="item.com_id"
                >
                  <!-- 头部区域 -->
                  <div class="cmt-header">
                    <!-- 头部左侧 -->
                    <div class="cmt-header-left">
                      <img :src="item.aut_photo" alt="" class="avatar">
                      <span class="uname">{{item.aut_name}}</span>
                    </div>
                    <!-- 头部右侧 -->
                    <div class="cmt-header-right">
                      <van-icon
                      name="like"
                      size="16"
                      color="red"
                      v-if="item.is_liking"
                      @click="likeOrDisLikeFn(item)"
                      />
                      <van-icon
                      name="like-o"
                      size="16"
                      color="gray"
                      v-else
                      @click="likeOrDisLikeFn(item)"
                      />
                    </div>
                  </div>
                  <!-- 主体区域 -->
                  <div class="cmt-body">
                    {{item.content}}
                  </div>
                  <!-- 尾部区域 -->
                  <div class="cmt-footer">{{formatTimeFn(item.pubdate)}}</div>
                </div>
              </div>
          </van-list>
    </div>

    <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="showCmtTop">
        <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
        <div class="ipt-cmt-div" @click="showCmtTop = false">发表评论</div>
        <div class="icon-box">
            <van-badge
            :content='totalCount'
            :max='99'
            @click.native="scrollToViewFn"
            >
                <van-icon name="comment-o" size="0.53333334rem" />
            </van-badge>
            <van-icon
            name="star"
            size="0.53333334rem"
            v-if="artObj.is_collected"
            @click="toggleCollectionFn"
            />
            <van-icon
            name="star-o"
            size="0.53333334rem"
            v-else
             @click="toggleCollectionFn"
            />
            <van-icon name="share-o" size="0.53333334rem" />
        </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div
    class="cmt-box van-hairline--top"
    v-else
    >
        <textarea
        placeholder="友善评论、理性发言、阳光心灵"
        v-focus
        @blur="onBlurFn"
        v-model.trim="cmtStr"
        @keydown.enter="publishCmtFn"
        ></textarea>
        <van-button type="default" :disabled='!cmtStr' @click="publishCmtFn">发布</van-button>
    </div>
  </div>

</template>

<script>
import {
  getArtCommentAPI, likeCmtAPI,
  disLikeCmtAPI, pubCmtAPI
} from '@/api/article'
import { Toast } from 'vant'
export default {
  name: 'comment',
  props: {
    // 文章对象//
    artObj: {
      type: Object,
      required: true
    }
  },
  data () {
    return {
      commentList: [], // 评论列表
      showCmtTop: true, // 控制品论两套标签的互斥显示 true 表示上可见
      totalCount: 0, // 评论总数
      cmtStr: '', // 评论内容
      loading: false,
      finished: false
    }
  },
  created () {
    //   获取文章列表
    this.getCommentList()
  },
  methods: {
    toggleCollectionFn () {
      this.artObj.is_collected = !this.artObj.is_collected
    },
    // 文本域失去焦点
    onBlurFn () {
      // 异步隐藏，让它不马上就隐藏
      setTimeout(() => {
        this.showCmtTop = true
      })
    },
    async getCommentList () {
      const res = await getArtCommentAPI({
        artId: this.artObj.art_id,
        offset: this.offset
      })
      // console.log(res)
      const { results, total_count: totalCount, last_id: lastId } = res.data
      //  结束请求的标志
      if (lastId === null || results.length < 10) {
        this.finished = true
      }
      // 保存每次请求返回的lastID值，为了给下次请求带过去做分页
      this.offset = lastId // 偏移量  加载更多
      // 合并数组
      this.commentList = [...this.commentList, ...results]
      this.totalCount = totalCount || ''
      this.loading = false
    },
    // 评论上拉加载更多
    onLoad () {
      //   获取文章列表
      this.getCommentList()
    },
    async likeOrDisLikeFn (item) {
      try {
        //   同步到后台
        item.is_liking ? await disLikeCmtAPI({
          comId: item.com_id
        }) : await likeCmtAPI({
          comId: item.com_id
        })
        // 1.取反后重新赋值
        item.is_liking = !item.is_liking
        Toast.success(item.is_liking ? '点赞成功' : '取消点赞成功')
      } catch (e) {
        Toast.fail(item.is_liking ? '点赞成功' : '取消点赞成功')
      }
    },
    // 评论滑动到相应的位置
    async scrollToViewFn () {
    // 真实DOM都在document(所以不再一个vue文件内), 也是可以获取的
      document.querySelector('.like-box').scrollIntoView({
        behavior: 'smooth'
      })
    },
    // 发表评论
    async  publishCmtFn () {
      try {
        // 要把一个合格的对象，不好弄，所以想同步到后台
      // 1.同步到后台
        const res = await pubCmtAPI({
          artId: this.artObj.art_id,
          data: this.cmtStr
        })
        //   console.log(res)
        // 2.添加到数组
        this.commentList.unshift(res.data.new_obj)
        this.cmtStr = ''

        // 异步隐藏，让它不马上就隐藏
        setTimeout(() => {
          this.showCmtTop = true
        })
        Toast.success('发布成功')
        this.totalCount++
      } catch (e) {
        Toast.fail('发布失败')
      }
    }
  }
}
</script>

<style scoped lang="less">
.com_list_content {
  // 让没有更多了显示出来，因为底部的盒子高为46 而且是固定定位
  padding-bottom: 46px;
}
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}
/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
